diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index cce0cc0..f79a69f 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -53,6 +53,7 @@ jobs:
             source $HOME/.cargo/env
 
           run: |
+            export CARGO_REGISTRIES_CRATES_IO_PROTOCOL=sparse
             $HOME/.cargo/bin/cargo test --release --target ${{ matrix.target }}
             $HOME/.cargo/bin/cargo test --release --features portable --target ${{ matrix.target }}